creating a booking form

i am trying to create a booking form.
book a room for a period of time. between to dates
i am creating a list (database) with each booking.
enter the booking details and a macro to add the details to ed of list.
i want to check to booking against the database, before i enter the booking to the list.

the problem is there are multiple entries for each room, can't use Vlookup.
there are multiple dates to be checked against each room eg if i try to create a booking for two weeks, i want to check that none of the dates within the range are already booked for that room.

i have tried a number of variences of lookup-match-index etc
i am proposing a list but i am very fluid regarding this.

rather than a solution perhaps some recommended reading or research would be much appreciated.